Device for the formation of the weft in bobbinless shuttle looms



Oct. 7, 1969 G. A. GRANDI 3,470,919

DEVICE FOR THE FORMATION OF THE-WEFT IN BOBBINLESS SHUTTLE LOOMS Filed Oct. 9, 1967 3 Sheets-Sheet 1 \\\\\\\y A 5mi., H461 fd 5M IN ENTOR.

Oct. 7, l1969 G. A. GRANDI 3,470,919

DEVICE FOR THE FORMATION 0F THE WEFT IN BOBBINLESS SHUTTLE LOOMS Filed Oct. 9, 1967 5 Sheets-Sheet f 12b, l 14a,

Oct. 7, 1969 G. A. GRANDI 3,470,919

DEVICE FOR THE FORMATION 0F THE WEFT IN BOBBINLESS SHUTTLE LOOMS Filed Oct. 9, 1967 3 SheetsSheet .it

29a, 31d Mc United States Patent O U.S. CL 139-16 6 Claims ABSTRACT OF THE DISCLOSURE A device for weft insertion applicable in a circular loom operating with a bobbin-less grippingshuttle and comprising gripping means on the shuttle for rgripping the weft yarn at the entrance into the shed, first clamping means at the entrance of the shed for clamping the free end of the weft yarn before 'it is gripped by that gripping means, second clamping means for clamping the free end of the weft yarn entrained by said gripping shuttle at the exit from said shed, means for releasing said clamping means in pre-established periods and cutting means for cutting the weft yarn at the entrance of said shed.

ythe problem of the formation of the weft in bobbin-less shuttle looms by providing a device with an extremely high shuttle speed and without operational interruptions of the shuttle, so that high fabric production may be obtained.

Another object of the invention is that of using members of especially reduced size and weight so that the movement of said members involves minimum inertias and their operative rapidity may consequently be eXtremely high.

A further object of the invention is that of providing a device which may be used with looms adapted to a simultaneous loom production of a plurality of fabrics, even fabrics of different weft aligned along the guide run of the shuttle.

A further object of the invention is that of providing a device for the formation of the weft which may be adapted to the production of fabrics of different width on a single loom and a plurality of fabrics on a single loom, so that the range of its use on a single loom is notably increased.

These and further objects, which will better appear hereinafter are achieved by a device according to the invention for the formation of the weft, characterized in that it comprises, in a weaving loom with a shuttle guide, a shuttle sliding in said guide and provided with a pincer adapted to entrain and carry an end of a weft thread, a distributor member `fast with said guide and situated, along the guide run of the shuttle, in an upstream zone with respect to the direction of advance of the shuttle, of the entrance section of the warp shed, a wedge-like retractor for the jaws of the pincer carried by said distributor, clamp means carried by said distributor member and adapted to cause the clamping of an end of a weft thread between the jaws of said pincer when said jaws are opened by said wedge so that the end of the weft thread is clamped between the jaws when the shuttle passes said wedge, and cutting means situated adjacent to said distributor member and adapted to cut the thread gripped and entrained by said pincers after said thread exits from the warp shed, a clamp member for the end of the. thread carried -by the shuttle pincer and situated along the shuttle 3,470,919 Patented Oct. 7 1969 guide, downstream, with respect to the direction of advance of said shuttle, from the exit section of the warp shed, a wedge-like diverger for the jaws of said pincer and rigid with said clamp member, entraining means adapted to entrain the end of the thread freed as a result of the diverging of the clamp jaws, said entraining means being rigi-d with said guide.

Further characteristics and advantages will appear more clearly from the following detailed description of an embodiment of the device according to the invention illustrated by way of non-limiting example in the accompanying drawings in which:

FIG. 1 shows a vertical section of a circular loom provided with a device according to the invention for the formation of weft, in which are shown the main members of a loom adapted to the simultaneous weaving of two independent cloths;

FIG. 2 shows a diagrammatic plan view of a portion of a loom reed-holder disc in which the positions of the characteristic members forming the device according to the invention are indicated;

FIG. 3 shows a partial section view of a detail of a distributor member at the moment at which a shuttle is adjacent thereto;

FIG. 4 shows a view of a gripper member for the end of the weft, when a shuttle is adjacent thereto;

FIG. 5 shows a lateral View of a shuttle cooperating with the device according to the invention;

FIG. 6` shows a plan view of the same shuttle;

FIG. 7 shows a lateral view of a detail of a pincer fast with the shuttle;

FIG. 8 shows the same detail in a cross-section of the shuttle;

FIG. 9 shows wedges mounted on the distributor and members in their alignment with the pincer of the shuttle;

FIGS. l0, 1l and l2 show a diagrammatic plan view of the sequence of turning operations of the device according to the invention.

With reference to said gures, the loom comprises a base 1, a vertical driving shaft 2 actuated by a motor 3 and engaged, through a cog wheel 4, with an internally toothed cog wheel 5 situated in the lower part of a sleeve member 6; said sleeve member 6 is positioned with its axis vertical and is associated to a co-aXial support column 7 so as to cause the rotation of said sleeve.

Reference numeral 8 indicates a thrust bearing which supports the weight of the sleeve 6. Said sleeve 6 is peripherally provided with an annular step 9, situated in an inclined plane with r-espect to the horizontal, in manner such as to form an inclined support. A reedholder disc 10 rests, by means of its annular flange 10a, on said inclined support and is substantially co-aXia-l to said rotating sleeve. Said reed-holder disc is provided along at least a circular arc and, in the ca-se shown, on two distinct successive circular sectors, each less than a semi-circle, with radical reeds 11. An arm 12, fast with said rotating sleeve 6, carries at one of its ends an electro-magnet 12a and is counter-weighted in 13. The electro-magnet rotates rigidly with the sleeve 6, entrained by said shaft 2, and is maintained facing a shuttle 14 arranged in a shed 15, whence said shuttle is caused to rotate.

Said shuttle 14 runs in an annular guide 16. Reference numeral 17 indicates healds, 18 indicates a lower ring with reeds aligning warp threads 19, 20 indicates warp beams, 21 indicates the woven fabric, 22 indicates the rings for the electrical connection with relative brushes 23; 24 indicates a device for preventing the rotation of the reed-holding disc 10 but which however allows said disc to undulate; '25 indicates an upper ring, 26 indicates the beam rollers, 26a indicates take up rollers; 27

indicates the external reels, 27a indicates a known thread braking device, said device 27a being positioned between the reel 27 and the thread distributor device 28; 30 a pair of cutters, 31 indicates a weft retaining clamp.

Passing to the details of the above-described members, it may be noted that rigid with the fixed framework is a substantially vertical guide 24a against which rolls a roll 24b supported by the reed-holder disc 10 and free to rotate about an axis passing through the centre of undulation. Said guide 24a co-operates with the roller 24b preventing the disc 10 from rotating but not from effecting vertical undulational movements.

The annular external edge b of the disc forms an in ternal edge of annular channel guide 16 whose external edge 10c is formed by an angled profile of circular perimeter and secured by known means to the reed-holder disc 10 in the peripheral zone of the latter. In such manner the upper plane of the teeth of the reed 11 forms the base of the guide 16 for said shuttle 14.

The shuttle 14 has a form analogous to that of the known bobbin type of shuttle. Advantageously the shuttle is light in weight and has transverse dimensions such as to enable free sliding along the rotary path of the guide 16. Said shuttle 14 carries, at the side thereof facing the inner wall of the annular guide 16 a magnetizable core indicated in broken lines with 14a. On the upper side of said shuttle 14 is provided a vertical grooving 14b in which a pincer is secured by known means 14g. Said pincer or gripping means 14e is formed by two elastic vertical plates or jaws 14d in mutual contact in -azone external to the grooving 14b and forming the gripping part of the pincer. The upper edges or free ends of the plates 14d are mutually separated so as to define a gap 14e adapted to facilitate the introduction between the two plates of a diverging means.

A horizontal grooving 141 is provided on the outer side of the one of said two plates 14d which is external with respect to guide 16. Said grooving 14jc is provided at the level of the zone of mutual contact between said plates 14d. Said plates 14d are provided in front and rear with a rest 14h for the positioning of the thread as will be seen hereinafter.

There now follows a detailed description of all those members which directly co-operate with the shuttle 14, during its movement, in the automatic formation of the weft. Such members have been previously mentioned and, more Iprecisely are: the thread distributor device 28, the cutters 30 and the weft retaining clamp 31.

The distributor device 28 is situated, along the annular 16 and in the direction of rotation of the shuttle 14, in a zone slightly in advance of the zone where the beginning part of the thread-carrying healds 17 are arranged. Said healds 17 form in known manner, the shed of the warp 15. Said distributor comprises a bracket block 28a carried by a vertical support 28b secured by known means to the section 10c forming the outer wall of the guide 16; by means of this arrangement the distributor 28 is rendered fast with the reed-holder disc 10.

The upper part of the block 28a extends horizontally to the central lane of the guide 16 and overhangs the latter (FIG. 3). In this zone supported from above by known means 28e, is a vertical blade member 29 with a wedge-like profile. Said `blade 29 is tapered in its bottom section 29a thereby providing an inclined edge allowing gradual engagement with the gripping means 14C. Said blade 29 is provided with a hole 29h in an intermediate position of its length. The blade 29 is situated above the -plane of the guide 16 at a height such that when the shuttle 14 passes below the blade 29 the latter may be progressively inserted (tapered end first) between the two elastic plates 14d forming the jaws of the pincer 14e` carried by said shuttle; the blade 29 thus diverges said plates 14d, this operation being facilitated by the shape of the mouth 14e. Further the hole 29 is situated at the same level, with respect to the plane of the guide 16,

as the zone of mutual contact of the two blades 14d and the rests 14h.

In the lower part of the block or rack 28a two tubes 28d and 28e are provided; saidtubes 28d and 28e converge towards the guide 16 and lie in a plane parallel to the plane of the guide 16, at the same level as the zone of contact between the two blades 14d and the hole 29d. The oblique pipe 28d forms a guide for the thread 27b coming from the reel 27, the pipe 28e has a radical development with respect to the circular guide and is designed to coincide with the hole 29h when the shuttle passes; said pipe 28a forms a seat in which a rod 32 slides longitudinally. The exit holes of the pipes 28d and 28e (on the side facing the annular guide 16) are as near as possible to one another. Said rod 32 is suitably shaped at the end facing the blade 29, for example, in the form of a fork or groove 32a. -It will be understood that the rod and the blade 29 provide a clamping means for the free end of the weft yarn. The opposite end of the rod 32 projecting from the block 28 is pivoted to 'an angled lever 33 engaged in 33a to a cantilever support 34, the upper end of which is secured to the block 28. Such pivoting is achieved by the engagement of a bolt 32a, associated in known manner to the end of the rod 32, inside a slot 33b situated at the end of the lever 33. A spiral spring 37, co-axial with said rod 32 and situated between the block 28a and a ferrule or annular stop 32C of the rod 32 maintains the latter in a normally retracted position within the pipe 28e. The lever 33 extends beyond the fulcrum 33a with an appendage 33C. Said appendage 33C is angled with respect to the lever 33 and is upwardly provided, at its free end, with a seat 33d designed to engage a stop or check 35 carried by said ring 25. Said stop 35 is of adjustable level by known means. Also in the warp shed, immediately before the healds 17, for example slightly downstream of the distributor 28 in the direction of rotation of the shuttle, is situated the cutting device 30 for the inserted weft pick. Said cutting device 30 comprises a first blade 30a rigidly secured to the body of the distributor 28, in vertical position, and a counterblade 30b hinged to the blade 30a. Said counter-blade 30b is subjected to the pulling action of a spring 30e anchored to the body of the distributor and which maintains the blade 30b diverged from the blade 30a. The counter-blade 30b is further provided with a seat 30d designed to engage, due to the rising of the reedholder disc (and analogously to what has been described for the lever 33e), a stop 36 rigid with the ring 25. The level of said stop 36 which may be adjusted by known means, is such that its contact with the counter-blade occurs, during the rise of the reed-holder rim, before the contact between the appendage 33e and the corresponding stop 35.

The weft retaining clamp 31 is situated, along the guide run of the shuttle, slightly downstream of the healds 17 and comprises a bracket 31a overhanging the guide 16 cantilever-wise and secured by known means to the angled profile 10c forming the external wall of the guide 16. The position of said bracket along the guide may be adjusted in known manner, by making it slide between the pair of parallel guides 31b and stopping it in the desired position, so as to be able to displace the weft retaining clamp 31 into the Iposition above indicated according to the width of cloth to be woven.

At the end of said bracket a U-shaped stirrup 31e` is secured by known means; the stirrup is formed of two symmetrical parts associated to one another, along the plane of symmetry and on the perpendicular to the central lane of said guide 16, by screw means; said parts lock between each other a vertical wedge-like blade 31d having a profile substantially similar to that of the wedge 29. The blade 31 has a tapered lower section and projects downwardly between the U-shaped prongs. Secured at the end of the prongs of said stirrup 31e are clamping means made of two horizontal elastic plates 31f defining a nip between their free extremities and extending backwardly with respect to the stirrup, that is in the opposite direction to the direction of motion of said shuttle, and converging in such direction until making mutual contact in a zonebehind the wedge-like blade member 31d, at the trajectory of the pincer 14.

Blade member 31d has an inclined edge to allow gradual engagement with grippingmeans 14.

Said plates 31jc diverge at their end section, beyond the zone of mutual contact and `form a mouth or opening 31g.

Said plates 31;c are at the same level, with respect to the plane" of the guide 16, as the zone of mutual contact of the plates 14d forming the pincer 14e of the shuttle 14a. The projecting portion of the wedge 31d is designed to enter only the upper part of the zone of mutual contact of the plates 14d. This is in order to avoid damaging the end of the weft pick in the opening phase of the pincer 14C.

The working is as follows:

When the driving shaft 2 rotates it entrains into rotation, by means of gear coupling 4 and 5, the sleeve 6. The reed-holder disc slides on the inclined guide 9, and prevented from rotating together with the sleeve 6 by the device 24, will be actuated with a motion which may be defined as a circular rocking. That is, considering any tooth of the comb, said tooth will periodically rise and lower between two fixed limited. The shuttle is situated in the guide 16 actuated by such rocking motion but is entrained in circular rotation by the electromagnet 12a, in synchronism with such undulations, whence said shuttle is not affected by the latter movement and it travels with substantially uniform speed along a track lying in a horizontal plane almost corresponding to the lowest position of the guide 16.

At the end of the cycle which precedes that now described the free end of the thread emanating from the spool 27 exits freely from the pipe 28d. In the case of the machine considered, provided with two arcs of reeds and such as to simultaneously weave two cloths, the shuttle, in the considered moment, is in a diametrically opposite position to the distributor 28` along the guide run, while the reed-holder disc 10 is raised by the part of the distributor taken into consideration, so as to obtain the commencement of the locking of the weft of the reeds 11 against the fabric. Slightly earlier, the fixed stop 35 engages the rest 33d determining the advance of the rod 32 in the pipe 28e. Said rod 32 with its forkshaped end 32a pushes the thread 27b immediately after its discharge from the pipe 28d and until said thread 27b is inserted in the hole 29b of the wedge 29.

At the re-lowering of the reed-holder disc 10, and while the shuttle is approaching, the rod 32 retracts in the pipe 28a, under the action of the spring 37, ready to repeat the setting-up operation of the thread in the following cycle.

When the shuttle arrives at the distributor 28 the wedge-like blade 29 is progressively inserted between the plates 14d of the pincer 14C of the shuttle and divides the plates.

As the shuttle advances the two plates 14d slide against the two opposite surfaces of the wedge tothe hole 29b. At this point the path of the plates of the pincer 14e` is intersected by the thread which, exiting from the pipe 28d, has been positioned with its end in the hole 29h as previously described. Then, since the elastic pressure exerted by the internal plate of the pincer 14c does not allow the end of the thread, compressed between said internal plate and said wedge, to come out of the hole 29b, and due to the advance of the shuttle, the front edge of the external plate advances and pushes the thread in front of it and causes the thread to be wound about it, dragging other thread from the spool 27.

When wedge has passed through zone of contact of the two plates 14d they lock the thread near its end allowing the now freed thread to leave the hole 29b. The thread thus remains firmly held since the end of the thread is turned in the direction opposite to the direction of advance of the shuttle. The thread becomes positioned in the rest 14h and partially lies in the protection groove 14)c of the external plate of the pincer 14e. The shuttle advances in the warp shed, and, when it exits from the shed, the weft thread becomes held by the clamp 31. Successively at the entrance zone of the shed the thread must be cut. For this operation the clamp 31 and the cutters 30E are provided.

With regardto the cutters 30, since from the entrance side the reed-holder disc has been re-raised, the seat 30d of the counter-blade 30h engages the fixed stop 36 whence said counter-blade is caused to downwardly rotate, against the action of the spring 30e, closing against the fixed blade 30a and cutting the thread. The final part of the rising stroke of the reed-holder disc initiates a new cycle with the setting up of the thread in the hole 29h by the rod 32.

Simultaneously, on the exit side of the shed, when the shuttle arrives at the clam-p 31 carrying, held between its pincer 14C, the end of the thread, the pincer becomes wedged, through the mouth 31g, between the two plates 31j, entraiuing behind the thread. The shuttle thus arrives at the wedge-like blade 31d which is then inserted between the plates 14d forming the pincer 14e. The plates 14d diverge freeing the end of the thread which is however retained by the elastic plates 31f which have returned into mutual contact after the passage of the pincer of said shuttle, Then the shuttle, by this time freed from the entrained thread, continues it run without pauses for the successive operations of insertion of the weft. In the case of the described machine, there being two cloths, for such operations a further distributor and clamp analogous and diametrically opposite to those described.

With the object of avoiding excessive stressing of the weft thread, wound about the external plate of the pincer 14e, when said pincer 14C, meets the receiving pincer formed by the plates 31f, the horizontal groove 14j is provided to protect the thread.

The invention as thus conceived may be subjected to numerous modifications and variations within the scope of the appended claims. Thus, for example, the device according to the invention may not only be used in circular looms but also rectilinear looms, parallel looms and the like. Moreover all the members may be replaced by other technically equivalent means.

I claim:

1. In a loom operating with a bobbin-less gripping shuttle including means for the formation of at least one shed of Warp threads, means defining a guide for the shuttle and passing through said shed, and means for imparting motion to said shuttle, a device for weft insertion comprising gripping means on said shuttle for gripping the weft yarn at the entrance into the shed, first clamping means at the entrance of said shed for clamping the free end of weft yarn before it is gripped by said gripping means,-

second clamping means for clamping the free end of said weft yarn entrained by said gripping shuttle at the exit from said shed, means for releasing said clamping means in pre-established periods and cutting means for cutting the weft yarn at the entrance of said shed and wherein, according to the improvement,

said gripping means comprise two plate elements having contacting free end portions projecting from the body of said shuttle and resilient portions urging said free end portions against each other, said first clamping means comprises a first blade member, in the path of said plate elements said first blade member having a through opening in the path of said plate elements, a pusher member in front of said opening, a distributor duct for guiding a free end of the weft thread in a position between said opening and said pusher member allowing said pusher member to insert said free end of the weft yarn into said 4. A- device according to claim 1, wherein said second opening, said second clamping means comprises two blade member has an edge inclined with respect of the plate members having contacting free extremity porpath of said plate elements and extending above said nip, tions defining a nip therebetween, said nip being loand said free end portions have their tips outwardly bent cated in the path of said free end portions of said 5 to diverge from one another thereby to allow a gradual v gripping means, said plate members having further engagement with said inclined edge.

resilient portions urging said free extremity portions 5. A device according to claim 1, wherein said loom is against each other, a second blade member arranged a circular loom.

in the path of said free end portions and near said 6. A device according to claim 1, wherein said means free extremity portions to spread apart said free end 10 for imparting motion to said shuttle is a rotating magnet. portions when said gripping means reach said second blade member and enter the nip defined by said References Cited free extremity portions to spread apart said free ex- UNITED STATES PATENTS tremity portions. 2, A device for weft insertion according to claim 1, 15 3105523 10/1963 Borrell 139-13 wherein at least one of said plate elements has a groove FOREIGN PATENTS at an outside surface thereof for receiving a weft thread 672 554 10/1963 Canada pomo thefem- 1,488,508 6/1967 France.

3. A device according to claim 1, wherein said first blade member has an edge inclined with respect to the 20 HENRY S TAUDON primary Examiner path of said plate elements and said free end portions have their tips outwardly bent to diverge from one another US- Cl- X-R- thereby to allow a gradual engagement with said inclined 139-125 edge. 

